The two blocks shown above are sliding across a frictionless surface by a force F from the left. The two blocks are not attached but the coefficient of static friction between the two is μs = 0.39. The mass of the smaller block is m1 = 14 kg and the mass of the larger block is m2 = 80 kg. a) What is the minimum force required to keep the smaller block from sliding down the larger block? I'm completely lost on this one. But here's what I tried. For M1: ΣFx = F - F12 ΣFy = Ff - mg = 0 = 0.39*N - (14)(9.81) so N = 352.15 For M2: ΣFx = F21 ΣFy = N - (80)(9.81) + Ff = 0 so N + Ff = (80)(9.81) so N = 647.46 I'm pretty sure what I have down so far is very wrong, so can someone help steer me in the right direction please?